from typing import Any

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.orm import Session

from app.api.v1.deps import get_current_active_user
from app.core.deps import get_db
from app.crud.cart import cart_item as cart_item_crud
from app.crud.product import product as product_crud
from app.models.user import User
from app.schemas.cart import (
    Cart,
    CartItem,
    CartItemCreate,
    CartItemUpdate,
    CartItemWithProduct,
)
from app.schemas.product import Product

router = APIRouter()


@router.get("/", response_model=Cart)
def read_cart(
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """
    Retrieve current user's cart.
    """
    cart_items = cart_item_crud.get_user_cart(db, user_id=current_user.id)

    # Fetch product details for each cart item
    items_with_products = []
    total = 0.0

    for item in cart_items:
        product = product_crud.get(db, id=item.product_id)
        if product:
            item_with_product = CartItemWithProduct.from_orm(item)
            item_with_product.product = Product.from_orm(product)
            items_with_products.append(item_with_product)
            total += product.price * item.quantity

    return {"items": items_with_products, "total": total}


@router.post("/items", response_model=CartItem)
def add_cart_item(
    *,
    db: Session = Depends(get_db),
    item_in: CartItemCreate,
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """
    Add item to cart.
    """
    # Check if product exists and is in stock
    product = product_crud.get(db, id=item_in.product_id)
    if not product:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Product not found",
        )

    if product.stock < item_in.quantity:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Not enough stock available. Only {product.stock} items left.",
        )

    # Create or update cart item
    cart_item = cart_item_crud.create_or_update(
        db, user_id=current_user.id, obj_in=item_in
    )
    return cart_item


@router.put("/items/{cart_item_id}", response_model=CartItem)
def update_cart_item(
    *,
    db: Session = Depends(get_db),
    cart_item_id: int,
    item_in: CartItemUpdate,
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """
    Update quantity of cart item.
    """
    cart_item = cart_item_crud.get(db, id=cart_item_id)
    if not cart_item or cart_item.user_id != current_user.id:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Cart item not found",
        )

    # Check if product has enough stock
    product = product_crud.get(db, id=cart_item.product_id)
    if not product:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Product not found",
        )

    if product.stock < item_in.quantity:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Not enough stock available. Only {product.stock} items left.",
        )

    cart_item = cart_item_crud.update(db, db_obj=cart_item, obj_in=item_in)
    return cart_item


@router.delete(
    "/items/{cart_item_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None
)
def remove_cart_item(
    *,
    db: Session = Depends(get_db),
    cart_item_id: int,
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """
    Remove item from cart.
    """
    cart_item = cart_item_crud.get(db, id=cart_item_id)
    if not cart_item or cart_item.user_id != current_user.id:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Cart item not found",
        )

    cart_item_crud.remove(db, id=cart_item_id)
    return None


@router.delete("/", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
def clear_cart(
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """
    Clear all items from cart.
    """
    cart_item_crud.clear_cart(db, user_id=current_user.id)
    return None